The Randomization and Analysis Core (Core D) is focused on empowering our scientific investigators with first-rate statistical reasoning and analytic support that are needed to ensure the successful implementation and analysis of the proposed Experience Corps (EC) Trials. It specifically aims to perform four key functions. First, the Core will support for the design and Implementation of randomization of EC schools and older adult volunteers. Second it will provide coordinated statistical support for validly addressing the aims of this Program Project by collaborating with investigators in all projects in the design of statistical analyses and standardizing the application of high-level analyses shared by multiple projects. Third, it will serve as an intellectual partnership and quantitative resource for other EC cores by assisting the Recruitment and Retention Core (Core B)'s evaluation of the effectiveness of recruitment, retention, and recruitment messages and strategies targeting different subgroups;assisting with the Data Collection and management Core (Core C)'s quality control analyses and development of analytic datasets;and contributing to the collective understanding by the Administrative Core (Core A) and project investigators of the results from specific studies. Finally, in collaboration with Core, C, Core D will support the needs of the Data safety and Monitoring Board by analysis of adverse events and provision of appropriate data in a timely manner. By bringing in a critical mass of dedicated statistical expertise, infrastructure, and staffing to this project, we will be able to overcome the serious challenges that community trials poses for statistical analysis and hence improve our ability to derive critical evidence that is needed locally and nationally to take a high quality program to scale to improve the health of our senior citizens and support the success of our children.